I wonder if some of you even wonder how Relic makes money.
Seriously you can't live with a single game release for about 5 years and give all the content to your players for free.
you dont have to sacrifice the integrity of gameplay to monetize a game. The game is already on shakey grounds with purchasable commanders. sc2 and dota2 have shown that there is no reason to sacrifice the integrity of the gameplay to remain profitable.
id rather see (and i would most certainly purchase) another expansion like the western fronts expansion way before i buy supply so i have the option to call in shock troops for a limited number of games before i have to buy them again.